Weak and Powerless (Columbine)

Mac, her friend Hannah, and her little brother Cas, are probably considered strange kids. They pay homage to two school shooters by trying to film a sequel to their infamous "Radioactive Clothing" video. And in doing so, they somehow end up back in time. Too early for the massacre to have happened. Before Eric and Dylan were even considering their plan for NBK.
Can they change the past to fix the future? Is preventing a nationwide tragedy really as simple as befriending two wayward kids? Or is there more at stake than Mac and Hannah could have ever predicted?
*Not my photo; just my edit.